Guide for the Forensic Documentation and Photography of Footwear and Tire Impressions at the Crime Scene
1.1 This Guide provides procedures for the documentation and photography of footwear and tire impressions at the crime scene.
1.2 The particular procedures and methods employed in a given case will depend on the evidence.
1.3 This Guide may not cover all aspects of unusual or uncommon conditions.
1.4 This Guide does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this Guide to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1.5 This Guide is not intended as a substitute for training in the forensic documentation and photography of footwear and tire track evidence. Completion of a training program and experience in these skills is essential to understanding and applying the principles outlined in this Guide.
1.6 This Guide relates to the still photography and written documentation of the recovery of footwear and tire impressions, as related to detailed physical comparisons that will be later made with known footwear and tires. Note: Videotaping, although adequate for providing overall views of the scene and evidence, is not adequate for detailed physical comparisons and is therefore not recommended.
3.1 The procedures outlined here are grounded in the generally accepted body of knowledge and experience in the fields of documentation and photography of footwear and tire impression evidence. By following these procedures, impressions can be properly documented and photographed.
3.2 Footwear and tire tread impressions are documented and photographed for future examination.
4.1 Footwear and tire impression evidence may have inherent limitations that can interfere with the procedures in this Guide. Limitations, when known, should be noted and recorded.
4.2 Limitations can be due to substrate features, quality of original impressions, and method of collection.
5. Equipment and Requirements
5.1 Photographic Equipment
Professional SLR film or digital camera (manual focus, detachable flash with 6 foot cable or flash with remote capability, sufficient resolution, timer or shutter cable cord or other remote control)
Appropriate color or black & white film or digital storage media
5.2 Tripod capable of various angles and positions
5.3 Dark cloth to block sun or bright ambient light
5.4 Long tape measure(s)
5.5 Finely divided rigid scale(s)
5.6 Placards with numbers or letters
5.7 Photo log
The following procedures may be used, as appropriate, for documenting and photographing footwear and tire impressions. The order of the following steps may vary.
6.1 Note case number, date, time, location of scene, conditions at scene (soil, weather, moisture, and substrate), scene responders.
6.2 Evaluate overall scene and available information.
6.3 Take overall scene photographs of footwear and tire impressions.
6.3.1 Preparation of a photo log is recommended.
6.3.2 Tire impressions should be photographed from several locations around the perimeter of the scene.
6.4 Establish path into scene with regard to preservation of evidence
6.5 Place identifying markers next to impressions. These assigned identifiers should be used to link the subsequent diagrams, photographs, and lift or cast of each impression.
6.6 Diagram impressions to record relationship to one another and direction of travel.
6.7 Take medium range photographs of selected impressions, including identifiers, in order to provide closer views of impressions and document their relative positions.
6.8 Measure vehicle track width, turning diameter, and wheel base of impressions if possible.
6.9 Take Examination Quality photographs.
Position camera on tripod with film plane parallel to impression
A rigid scale should be included in every photograph
Place scale next to and along length of impression at same plane as bottom of impression
For a long tire impression, in addition to the rigid scale, a long tape measure should be placed along the full length of the impression being photographed, to aid in reconstruction of the impression using the series of photographs.
Fill frame with impression and scale.
Focus on the bottom of the impression rather than the scale.
Photograph the impression using flash held at an oblique angle.
Flash should be held 4 to 5 feet away from and directed at impression.
For a long tire impression, a series of overlapping photographs should be taken.
Take additional photographs with flash at multiple positions around impression.
An identifier should be included in each photograph.
Use dark cloth to block bright sun or ambient light which is striking impression.
For impressions in snow, highlighting sprays, such as Snow Print Wax or aerosol paint, may be used to increase the contrast.
6.10 Collect elimination impressions and/or photographs of footwear and tires of non-suspect persons and vehicles.
6.10.1 Document brand name, manufacturer, model, size, and DOT information of tires.
6.10.2 Document brand, style, and size of footwear.